Augmentation of severly resorbed alveolar crests with bovine bone blocks: A human histology pilot study.

BACKGROUND: Allo-/xenogenic bone blocks are used to treat bone defects. Few human histologic studies are found on their integration and capacity to augment new bone. PURPOSE: To study incorporation and stability of collagenated bovine bone blocks (CBB). Short term effects, histology, and morphometry on biopsy specimens are presented. MATERIALS AND METHODS: Nine patients exhibiting extremely narrow alveolar ridges had CBB adapted and fixed to the recipient bone and covered with collagen barriers. At median 6 months healing (range 2-14 months) biopsies were harvested and dental implants placed. Evaluation was done on the handling, primary healing together, and morphologic assessments of the biopsies. RESULTS: New bone varied from 7.7% to 34.5%, lowest value being found in a patient showing graft exposure. Residual biomaterial varied between 2.9% and 48.2%. Implant placement was successful in all cases and all patients were rehabilitated with fixed superstructures. Several critical issues are discussed on the clinical handling of the material for example, soft tissue management and use of barrier membranes. CONCLUSIONS: CBB was found to integrate well in a predictable way. New bone could be seen at early time points and may shorten treatment time with implants in cases with thin alveolar ridges.